Sleeker, larger, lighter, more powerful, faster, a good deal less thirsty and, according to Porsche, better to drive. That's the short story on the new Porsche 911, revealed here officially for the first time.

Known internally as the 991, the new 911 is the next generation in an illustrious 48-year history. The world debut will be at next month's Frankfurt motor show, prior to going on sale in North America in December.

Following the example of its strong-selling predecessor, the 2012 Porsche 911 will initially be sold in rear-wheel drive Carrera and Carrera S coupe guise.

In 2012, there will be a further flood of new 911 models, with various cabriolet and all-wheel drive variants paving the way for the introduction of a range-topping 911 Turbo packing 523 hp from a further-developed version of the exiting model's turbocharged 3.8-liter flat-six engine in 2013.

The first official pictures of Porsche's iconic coupe reveal a bolder look for the 2012 911, whose exterior receives lightly altered dimensions, freshly interpreted detailing, added sculpturing and optimized aerodynamics. It was designed under the watch of Porsche design boss Michael Mauer. The visual changes, in keeping with the evolutionary approach taken since its introduction at the Frankfurt motor show back in 1963, are subtle but effective enough to set the new car apart from its popular predecessor, providing it with clear links to the past but with sufficient modernity to give it a contemporary air.

Official dimensions are yet to be revealed, but officials from Porsche's Zuffenhausen headquarters in Germany confirm the new 2012 911 is 2.2 inches longer, 2.6 inches wider and 0.4 of an inch lower than its immediate predecessor at 176.8 inches in length, 73.7 inches in width and 51.1 inches in height. It also rides on a wheelbase that has been extended by 3.9 inches, to 96.5 inches.

At the front, the most prominent design feature continues to be the traditional round headlamps. Set out on the front of wider and slightly higher front fenders, they have been made even bigger and house more complex internal graphics than before. The reworked headlamps--which come with distinctive LED main-beam projectors similar to those offered on the Porsche Cayenne and the Panamera as optional equipment--are complimented by curvy new LED daytime running lamps on the leading edge of a reshaped bumper that borrow their shape from those seen on the 918 Spyder concept.

Along the sides, there are larger wheel houses, large and more angular exterior mirrors that sit outboard on the doors rather than in the blanked-off quarter-panel at the base of the A-pillar, a slightly higher waistline, marginally shallower and more elongated glasshouse, a more defined crease line running underneath the doors, wider rear fenders and a more heavily angled rear window.

The rear is distinguished by a thin line of LED tail lamps that sit underneath a prominent lip that forms the tailing edge of the engine lid and wrap further around into the rear fenders than before. Changes made to the design of the rear wing, which continues to deploy at 75 mph, also serves to reduce lift without any detrimental effort to the low level of drag. Forming the upper part of the engine lid, the wing is wider, has three instead of the previous five air ducts to feed cooling air into the engine bay and now extends variably for smoother introduction of additional downforce at the rear.

While few are likely to mistake the new 911 for anything but a Porsche, the new model also carries Porsche badges along with individual model identification on the upper edge of a more shapely rear bumper for the first time.

In the interests of production efficiency and providing parts-sharing compatibility with next year's Boxster/Cayman, the Porsche 911 continues to be based around a unitary monocoque structure using a platform fabricated from high-strength steel. But in a clear break from tradition, the latest model gets a predominately aluminum body shell.

The move away from steel for the complete body was in an effort to cut weight, with Porsche claiming a reduction of 99 pounds for the 911 Carrera, although there is no official figure yet. But even with an increase to take into account the added dimensions and greater levels of standard equipment, it's lighter than the old model.

Engines and Gearboxes

Porsche is following the strategy taken with the outgoing 911 by offering the choice of two standard naturally aspirated, horizontally opposed six-cylinder engines--both running the latest in piezo-guided direct injection and--as 48 years of tradition dictates--mounted aft of the rear axle line.

The big news is the downsizing of the base unit in the 911 Carrera. It drops in capacity from 3.6 liters to 3.4-liters, the same as the Boxster/Cayman S. But while the engine in the Boxster/Cayman S delivers 316 hp, the 911 Carrera packs a sturdier 345 hp, up 4 hp over the old model's 3.6-liter engine.

The 2012 Carrera S continues with a 3.8-liter unit, but it has been reworked with detailed changes to the induction and exhaust, liberating an added 14 hp for a total of 394 hp. The two models are distinguished at the rear: the 2012 Carrera continues to feature two oval-shape exhaust pipes while the Carrera S gets four round pipes.

Eschewing the traditional six-speed gearbox that has been a 911 mainstay since 1993, the model gets a new seven-speed gearbox. Details remain scarce, but it has been described to Autoweek as being closely related to the new car's optional seven-speed dual-clutch PDK gearbox, itself manufactured by German gearbox specialist, ZF.

Porsche has yet to reveal the ratios it has chosen for the gearboxes, although with 20-inch wheels now optional across the lineup, they are expected to alter slightly on those used by the outgoing model. In a move that makes the new 911 one of the most economical cars in its class, both gearboxes have been engineered to support standard automatic stop/start and brake-energy recuperation. The PDK also gets a so-called sailing function that automatically opens the clutch to allow the new Porsche 911 to coast with only minimal mechanical drag on a trailing throttle.

There are improvements in straight-line performance. However, they are minimal compared with the gains made by the last 911 model change in 2004. Porsche claims a 0-to-62-mph time of 4.4 seconds for the Carrera running the optional PDK gearbox and Sports Chrono package, an improvement of 0.3 second, with the similarly specified 2012 Carrera S put at 4.1 seconds, or 0.3 second faster than before. No top-speed claims have been made, however, various aerodynamic tweaks are said to see the Carrera top 180 mph, with the Carrera S extending beyond 190 mph.

Chassis

There have been some significant changes to the chassis as a result of the lengthening of the wheelbase in the never-ending quest to further improve the new 911's handling, grip and ride. Porsche is not going into great detail right now but confirms that the front track has been increased considerably in length, while the multilink rear-axle assembly has been completely redesigned with new pick-up points in a bid to provide both improved longitudinal stability at high speed and more secure lateral properties.

Having dispensed with linear steering for a variable-rate setup for the last 911, its engineers have gone one step further by dropping hydraulic actuation for a new electromechanical arrangement as part of the drive to reduce weight and lower fuel consumption. Another new feature is what Porsche dubs active chassis control, an active roll-stabilization system conceived to give the new 911 reduced lean and greater wheel control for higher cornering speeds.

Continuing developments seen on the outgoing model, the 2012 Porsche 911 will also come with active suspension management (PASM), which will continue to be optional on the Carrera and standard on the Carrera S. It features adaptive constantly variable dampers and an ability to alter the throttle mapping. An optional sports suspension brings firmer springs and dampers, reduced ride height and a more aggressively configured limited-slip differential.

Interior

The interior of the latest 911, which continues with a 2+2 layout, is all-new. Leaning heavily on the design of the interior seen in the second-generation Cayenne and Panamera, its adoption forms part of a conscious effort to provide the new 911 with higher overall perception of quality than ever before, while also providing added economies of scale through additional parts sharing with Porsche's four-door models.

The outboard ignition switch and classic five-dial instruments remain, although one of them is now a high-resolution multifunction screen. Set in front of the driver is a large (gray-faced in the Carrera S model) rev counter, with a smaller speedometer offset to the left. They are flanked by oil temperature and pressure, water temperate and fuel gauges. The instruments sit behind a new thick-rimmed, three-spoke multifunction steering wheel on models sporting the optional Sport Chrono package. A broader center console houses a larger color monitor for the navigation and entertainment functions as well as the controls for the air conditioner, while a slightly higher-set gear lever brings a crucial change in ergonomics.

The center console houses more switchgear than before, reflecting a greater level of standard and optional equipment. Along with providing the Porsche 911 with a more contemporary driving environment, the new interior also provides added practicality with door-mounted bins. Accommodation is also improved, although this first picture reveals that the footwells continue to suffer from intrusion from the front wheel arches. The 3.9-inch increase in wheelbase has, however, created added space in back.